(A) Co-immunoprecipitation of JBP3, Wdr82 and PNUTS. Cell extracts from bloodstream form T. brucei cells that endogenously express PTP- and HA-tagged versions of the indicated proteins were purified by protein A affinity and analyzed by western blotting with anti-HA, anti-protein A and anti-La. Equal cell equivalents of input (IP), unbound (U) and bound (B) fractions were loaded on the gel. (B) PNUTS, Wdr82, and JBP3 co-migrate following sucrose gradient fractionation. Cell extracts from BSF T. brucei cells that endogenously express PNUTS-PTP and JBP3-HA or express PNUTS-PTP and WDR82-HA were loaded onto 5–50% sucrose gradients and analyzed by density gradient centrifugation. Equal volumes of each fraction were analyzed by western blotting. Migration of PNUTS, JBP3 and WDR82 are shown in the gradient. The PNUTS and WDR82 signals were obtained from the same gradient and the JBP3 signal obtained from the other cell line applied to a parallel gradient. Molecular markers were applied to a parallel gradient.